Exercise 1.  Give a parametrization of each contour.  

1 (a).  [Graphics:Images/ContourIntegralModHome_gr_1.gif],  as indicated in Figure 6.11.

                    [Graphics:Images/ContourIntegralModHome_gr_2.gif]

                              Figure 6.11.  The contour  [Graphics:Images/ContourIntegralModHome_gr_3.gif].   Where
                              [Graphics:Images/ContourIntegralModHome_gr_4.gif]  for  [Graphics:Images/ContourIntegralModHome_gr_5.gif],    and   
                              [Graphics:Images/ContourIntegralModHome_gr_6.gif]  for  [Graphics:Images/ContourIntegralModHome_gr_7.gif].

Solution 1 (a).

See text and/or instructor's solution manual.

Answer.   [Graphics:../Images/ContourIntegralModHome_gr_8.gif]  for  [Graphics:../Images/ContourIntegralModHome_gr_9.gif],    and   [Graphics:../Images/ContourIntegralModHome_gr_10.gif]  for  [Graphics:../Images/ContourIntegralModHome_gr_11.gif].

Solution.  The contour  [Graphics:../Images/ContourIntegralModHome_gr_12.gif]  consists of  

[Graphics:../Images/ContourIntegralModHome_gr_13.gif]:  the first quadrant portion of  [Graphics:../Images/ContourIntegralModHome_gr_14.gif] starting at [Graphics:../Images/ContourIntegralModHome_gr_15.gif] and ending at [Graphics:../Images/ContourIntegralModHome_gr_16.gif],  and  

[Graphics:../Images/ContourIntegralModHome_gr_17.gif]:  a line segment starting at  [Graphics:../Images/ContourIntegralModHome_gr_18.gif]  and ending at  [Graphics:../Images/ContourIntegralModHome_gr_19.gif].

Since  [Graphics:../Images/ContourIntegralModHome_gr_20.gif]  for  [Graphics:../Images/ContourIntegralModHome_gr_21.gif]  is a parameterization of the circle  [Graphics:../Images/ContourIntegralModHome_gr_22.gif],

we see that  [Graphics:../Images/ContourIntegralModHome_gr_23.gif]  for  [Graphics:../Images/ContourIntegralModHome_gr_24.gif]  will start at  

[Graphics:../Images/ContourIntegralModHome_gr_25.gif]   and end at  

[Graphics:../Images/ContourIntegralModHome_gr_26.gif].  

                                        [Graphics:../Images/ContourIntegralModHome_gr_27.gif]

                    The curve  [Graphics:../Images/ContourIntegralModHome_gr_28.gif]   for   [Graphics:../Images/ContourIntegralModHome_gr_29.gif].  

In Section 1.6, we saw that an equation of the straight line segment beginning at [Graphics:../Images/ContourIntegralModHome_gr_30.gif] and ending at [Graphics:../Images/ContourIntegralModHome_gr_31.gif]  is:

[Graphics:../Images/ContourIntegralModHome_gr_32.gif]  

For this exercise we have   [Graphics:../Images/ContourIntegralModHome_gr_33.gif]   and   [Graphics:../Images/ContourIntegralModHome_gr_34.gif]

                              [Graphics:../Images/ContourIntegralModHome_gr_35.gif]

And if the parameter is adjusted to be the interval  [Graphics:../Images/ContourIntegralModHome_gr_36.gif] then we could use

                              [Graphics:../Images/ContourIntegralModHome_gr_37.gif]  for  [Graphics:../Images/ContourIntegralModHome_gr_38.gif].  

                                        [Graphics:../Images/ContourIntegralModHome_gr_39.gif]

                    The curve  [Graphics:../Images/ContourIntegralModHome_gr_40.gif]  for  [Graphics:../Images/ContourIntegralModHome_gr_41.gif].  

 

                                        [Graphics:../Images/ContourIntegralModHome_gr_42.gif]

                    Figure 6.11.  The contour  [Graphics:../Images/ContourIntegralModHome_gr_43.gif].  Where
                    [Graphics:../Images/ContourIntegralModHome_gr_44.gif]   for  [Graphics:../Images/ContourIntegralModHome_gr_45.gif],  and
                    [Graphics:../Images/ContourIntegralModHome_gr_46.gif]  for  [Graphics:../Images/ContourIntegralModHome_gr_47.gif].

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This solution is complements of the authors.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(c) 2008 John H. Mathews, Russell W. Howell